Add XML object header/kk:metadata parser functions that know how to t…

…hrow ConversionError if mandatory information is not found in parsed XML object

src/transform/index.js

@@ -9,7 +9,7 @@ import convertRecord from './convert';
 import createValidator from '../validate';
 import filterAndCreateValueInterface from './filter';
 
-import {convertToObject} from './xmlParser';
+import {convertToObject, getMetadataHeader, getRecordMetadata} from './xmlParser';
 import {parseHeaderInformation} from './convert/util';
 
 import {sourceConfig} from '../config';
@@ -66,7 +66,9 @@ export default convertOpts => (stream, {validate = true, fix = true} = {}) => {
       .on('tag:record', async xmlRecordEntry => {
         try {
           // Destructuring to get the header + metadata from the xml parsed to object
-          const {record: {header: [headerValue], metadata: [{'kk:metadata': [recordMetadata]}]}} = await convertToObject(xmlRecordEntry);
+          const xmlObject = await convertToObject(xmlRecordEntry);
+          const headerValue = getMetadataHeader(xmlObject?.record?.header);
+          const recordMetadata = getRecordMetadata(xmlObject?.record?.metadata);
 
           if (!headerValue) {
             throw new Error('Could not find header information for record, cannot process');

src/transform/xmlParser.js

@@ -1,6 +1,7 @@
 import {Parser} from 'xml2js';
 import {toXml} from 'xml-flow';
 import {DOMParser} from '@xmldom/xmldom';
+import ConversionError from './convert/conversionError';
 
 /**
  * Convert XML to JS object
@@ -28,3 +29,32 @@ export function convertToObject(node) {
     });
   }
 }
+
+
+export function getMetadataHeader(xmlObjectRecordHeader) {
+  if (!xmlObjectRecordHeader || !Array.isArray(xmlObjectRecordHeader) || xmlObjectRecordHeader.length === 0) {
+    throw new ConversionError({}, 'XML record header could not be read');
+  }
+
+  return xmlObjectRecordHeader[0];
+}
+
+export function getRecordMetadata(xmlObjectRecordMetadata) {
+  // const {record: {header: [headerValue], metadata: [{'kk:metadata': [recordMetadata]}]}} = await convertToObject(xmlRecordEntry);
+
+  if (!xmlObjectRecordMetadata || !Array.isArray(xmlObjectRecordMetadata) || xmlObjectRecordMetadata.length === 0) {
+    throw new ConversionError({}, 'XML record metadata could not be read');
+  }
+
+  const [firstEntry] = xmlObjectRecordMetadata;
+  if (typeof firstEntry !== 'object' || !Object.keys(firstEntry).includes('kk:metadata')) {
+    throw new ConversionError({}, 'XML record metadata did not contain kk:metadata');
+  }
+
+  const kkMetadata = firstEntry['kk:metadata'];
+  if (!Array.isArray(kkMetadata) || kkMetadata.lenght === 0) {
+    throw new ConversionError({}, 'XML record metadata kk:metada was empty');
+  }
+
+  return kkMetadata[0];
+}